| Message ID | 20241023035213.517386-1-wangliang74@huawei.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 9ab5cf19fb0e4680f95e506d6c544259bf1111c4 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net,v2] net: fix crash when config small gso_max_size/gso_ipv4_max_size | expand |
On Wed, Oct 23, 2024 at 5:34 AM Wang Liang <wangliang74@huawei.com> wrote: > > Config a small gso_max_size/gso_ipv4_max_size will lead to an underflow > in sk_dst_gso_max_size(), which may trigger a BUG_ON crash, > because sk->sk_gso_max_size would be much bigger than device limits. > Call Trace: > tcp_write_xmit > tso_segs = tcp_init_tso_segs(skb, mss_now); > tcp_set_skb_tso_segs > tcp_skb_pcount_set > // skb->len = 524288, mss_now = 8 > // u16 tso_segs = 524288/8 = 65535 -> 0 > tso_segs = DIV_ROUND_UP(skb->len, mss_now) > BUG_ON(!tso_segs) > Add check for the minimum value of gso_max_size and gso_ipv4_max_size. > > Fixes: 46e6b992c250 ("rtnetlink: allow GSO maximums to be set on device creation") > Fixes: 9eefedd58ae1 ("net: add gso_ipv4_max_size and gro_ipv4_max_size per device") > Signed-off-by: Wang Liang <wangliang74@huawei.com> > --- Thanks for this fix ! Reviewed-by: Eric Dumazet <edumazet@google.com>
Thank you very much for your suggestions! -----邮件原件----- 发件人: Eric Dumazet <edumazet@google.com> 发送时间: 2024年10月23日 14:44 收件人: wangliang (CI) <wangliang74@huawei.com> 抄送: davem@davemloft.net; kuba@kernel.org; pabeni@redhat.com; idosch@nvidia.com; kuniyu@amazon.com; stephen@networkplumber.org; dsahern@kernel.org; lucien.xin@gmail.com; yuehaibing <yuehaibing@huawei.com>; zhangchangzhong <zhangchangzhong@huawei.com>; netdev@vger.kernel.org; linux-kernel@vger.kernel.org 主题: Re: [PATCH net v2] net: fix crash when config small gso_max_size/gso_ipv4_max_size On Wed, Oct 23, 2024 at 5:34 AM Wang Liang <wangliang74@huawei.com> wrote: > > Config a small gso_max_size/gso_ipv4_max_size will lead to an > underflow in sk_dst_gso_max_size(), which may trigger a BUG_ON crash, > because sk->sk_gso_max_size would be much bigger than device limits. > Call Trace: > tcp_write_xmit > tso_segs = tcp_init_tso_segs(skb, mss_now); > tcp_set_skb_tso_segs > tcp_skb_pcount_set > // skb->len = 524288, mss_now = 8 > // u16 tso_segs = 524288/8 = 65535 -> 0 > tso_segs = DIV_ROUND_UP(skb->len, mss_now) > BUG_ON(!tso_segs) > Add check for the minimum value of gso_max_size and gso_ipv4_max_size. > > Fixes: 46e6b992c250 ("rtnetlink: allow GSO maximums to be set on > device creation") > Fixes: 9eefedd58ae1 ("net: add gso_ipv4_max_size and gro_ipv4_max_size > per device") > Signed-off-by: Wang Liang <wangliang74@huawei.com> > --- Thanks for this fix ! Reviewed-by: Eric Dumazet <edumazet@google.com>
Hello: This patch was applied to netdev/net.git (main) by Jakub Kicinski <kuba@kernel.org>: On Wed, 23 Oct 2024 11:52:13 +0800 you wrote: > Config a small gso_max_size/gso_ipv4_max_size will lead to an underflow > in sk_dst_gso_max_size(), which may trigger a BUG_ON crash, > because sk->sk_gso_max_size would be much bigger than device limits. > Call Trace: > tcp_write_xmit > tso_segs = tcp_init_tso_segs(skb, mss_now); > tcp_set_skb_tso_segs > tcp_skb_pcount_set > // skb->len = 524288, mss_now = 8 > // u16 tso_segs = 524288/8 = 65535 -> 0 > tso_segs = DIV_ROUND_UP(skb->len, mss_now) > BUG_ON(!tso_segs) > Add check for the minimum value of gso_max_size and gso_ipv4_max_size. > > [...] Here is the summary with links: - [net,v2] net: fix crash when config small gso_max_size/gso_ipv4_max_size https://git.kernel.org/netdev/net/c/9ab5cf19fb0e You are awesome, thank you!
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index e30e7ea0207d..2ba5cd965d3f 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -2032,7 +2032,7 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = { [IFLA_NUM_TX_QUEUES] = { .type = NLA_U32 }, [IFLA_NUM_RX_QUEUES] = { .type = NLA_U32 }, [IFLA_GSO_MAX_SEGS] = { .type = NLA_U32 }, - [IFLA_GSO_MAX_SIZE] = { .type = NLA_U32 }, + [IFLA_GSO_MAX_SIZE] = NLA_POLICY_MIN(NLA_U32, MAX_TCP_HEADER + 1), [IFLA_PHYS_PORT_ID] = { .type = NLA_BINARY, .len = MAX_PHYS_ITEM_ID_LEN }, [IFLA_CARRIER_CHANGES] = { .type = NLA_U32 }, /* ignored */ [IFLA_PHYS_SWITCH_ID] = { .type = NLA_BINARY, .len = MAX_PHYS_ITEM_ID_LEN }, @@ -2057,7 +2057,7 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = { [IFLA_TSO_MAX_SIZE] = { .type = NLA_REJECT }, [IFLA_TSO_MAX_SEGS] = { .type = NLA_REJECT }, [IFLA_ALLMULTI] = { .type = NLA_REJECT }, - [IFLA_GSO_IPV4_MAX_SIZE] = { .type = NLA_U32 }, + [IFLA_GSO_IPV4_MAX_SIZE] = NLA_POLICY_MIN(NLA_U32, MAX_TCP_HEADER + 1), [IFLA_GRO_IPV4_MAX_SIZE] = { .type = NLA_U32 }, };
Config a small gso_max_size/gso_ipv4_max_size will lead to an underflow in sk_dst_gso_max_size(), which may trigger a BUG_ON crash, because sk->sk_gso_max_size would be much bigger than device limits. Call Trace: tcp_write_xmit tso_segs = tcp_init_tso_segs(skb, mss_now); tcp_set_skb_tso_segs tcp_skb_pcount_set // skb->len = 524288, mss_now = 8 // u16 tso_segs = 524288/8 = 65535 -> 0 tso_segs = DIV_ROUND_UP(skb->len, mss_now) BUG_ON(!tso_segs) Add check for the minimum value of gso_max_size and gso_ipv4_max_size. Fixes: 46e6b992c250 ("rtnetlink: allow GSO maximums to be set on device creation") Fixes: 9eefedd58ae1 ("net: add gso_ipv4_max_size and gro_ipv4_max_size per device") Signed-off-by: Wang Liang <wangliang74@huawei.com> --- net/core/rtnetlink.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)